Field of the Invention
The present invention relates to a transporting apparatus, a developing apparatus and an image forming apparatus, and more specifically, a transporting apparatus that transports a developer within a developer vessel, and a developing apparatus and an image forming apparatus.
Description of the Related Art
An example of a conventional developing apparatus is disclosed in Japanese patent application laying-open No. 2011-2767 [G03G 15/08] (Patent Literature 1) laid-open on Jan. 6, 2011. The developing apparatus of the patent literature 1 is a developing apparatus that adopts a trickle development system among electrophotography system using a developer that consists of two components, a toner and a carrier. Briefly describing, the trickle development system means a technology that a new carrier is mixed to a toner in a toner cartridge with a predetermined ratio, and the new carrier is supplied to a developing apparatus with supply of the toner, and a carrier that deteriorated is sequentially replaced with the new carrier by discharging the surplus developer from the developing apparatus.
In the technology of the patent literature 1, a developer supplying/collecting portion and a developer churning portion are provided adjacent to each other and form a circulation path of the developer within the developer vessel. The developer supplying/collecting portion is provided with a transporting member (screw) that supplies a toner to a developer bearing member and transports a developer in a longitudinal direction to send the developer to the developer churning portion. Furthermore, the developer churning portion is provided with two churning members (screws) adjacent to each other, which transport the developer in a direction reverse to a transporting direction by the transporting member while churning to send to the developer supplying/collecting portion. Then, there is provided with, in a downstream side of a developer transporting direction of a first churning member, a braking portion that suppresses discharge of the developer, and a developer discharge portion that comprises a developer discharge port is provided in a downstream side than the braking portion. The braking portion is provided with a disk that faces a direction orthogonally intersecting the developer transporting direction and a reverse winding portion in an upstream side of the developer transporting direction than the disk.
In the technology of the patent literature 1, an amount of the developer that is discharged from a discharge portion (developer discharge port) is suppressed by providing the braking portion in the downstream side of the developer transporting direction of the first churning member. However, since the braking portion is provided on a line that is extended coaxially with the first churning member, the developer transported by the first churning member flows into the discharge portion more than required by an impetus thereof. Furthermore, there is an occasion that the developer flows into the discharge portion more than required due to splash raising of the developer by rotation of the churning member (screw), an internal pressure difference that occurs by rotation of a developing roller (magnet roller) between the developer supplying/collecting portion and the developer churning portion and the discharge portion, etc. That is, with the technology of the patent literature 1, it is impossible to say that discharge control of the developer is enough, and therefore, there is a possibility that a developer may be discharged excessively.